
public class Variable{
	public static void main(String[] args) {
		//整型变量
		//int a = 10; //定义一个整型变量
		//System.out.println(a);
		
		//System.out.println(Integer.MIN_VALUE-1); // int 的最小值
		//System.out.println(Integer.MAX_VALUE+1); // int 的最大值
		
		//长整型变量
		//long num = 10L; // 定义一个长整型变量, 初始值写作 10l 也可以(小写的 L, 不是数字1).
		//System.out.println(num) ;
		
		//System.out.println(Long.MIN_VALUE); // long 的最小值
		//System.out.println(Long.MAX_VALUE); // long 的最大值
		
		//双精度浮点型变量
		//double num = 1.0;
		//System.out.println(num);
		
		//int a = 1;
		//double b = 2.0;
		//System.out.println(a / b);
		
		//double num = 1.1;
		//System.out.println(num * num);
		
		//单精度浮点型变量
		//float num = 1.0f; // 写成 1.0F 也可以
		//System.out.println(num);
		
		//字符类型变量
		//char ch = 'a';
		//char ch = '中';
		//System.out.println(ch);
		
		//字节类型变量
		//byte value = 10;
		//System.out.println(value);
		
		//短整型变量
		//short value = 10;
		//System.out.println(value);
		
		//布尔类型变量
		//boolean value = true;
		//System.out.println(value);
		//System.out.println(value*1);
		
		//字符串类型变量
		//String name = "zhangsan";
		//System.out.println(name);
		
		// 创建一个字符串 My name is "张三"
		//String name = "My name is \"张三\"";
		//System.out.println(name);
		
		//字符串的 + 操作
		//String a = "hello";
		//String b = "world";
		//String c = a + b;
		//System.out.println(c);
		
		//字符串和整数进行拼接
		//String str = "result = ";
		//int a = 10;
		//int b = 20;
		//String result = str + a + b;
		//System.out.println(result);
		
		//int a = 10;
		//int b = 20;
		//System.out.println("a = " + a + ",b = " + b);
		
		int a = 10;
        int b = 20;
        System.out.println(a+b+"hello");
	}
}